The invention relates to a device for binding together a stack of document sheets and optionally for depositing such a bound stack in a file with a filing mechanism, comprising a base plate to be disposed below the document stack, a cover plate to be disposed on the document stack, at least one flexible binding tongue strip fixable and/or fixed to the base plate, whose two binding tongues, for the purpose of binding together the document sheets, are threaded through paired perforations in the document stack and the cover plate and are bent back at the ends on to the cover plate above the document stack, as well as at least one cover profile rail mountable on the cover plate, including the binding tongue ends, with undercut longitudinal edges for encompassing the longitudinal edges of the cover plate.
A device of this type is disclosed in European Patent 0 654 362 by the Applicant. This has a first feature in that the bent-back binding tongue plates are slightly inclined relative to the longitudinal axis of the cover plate and therefore run past next to one another. The one-piece, mounted cover profile bar therefore in every case finds a frictionally locking grip, since in the closed position neither locking nor hooking on the bent-back binding tongue ends is possible. The cover profile bar can therefore slip down from the cover plate if the document stack concerned is taken from a file, so that perforations penetrating all layers of the stack as well as the binding mechanism are no longer penetrated by the file clips. In Such a case there is a risk that the cover profile bar can pass unnoticed into an exposed position and can for example be bent there. Furthermore, in order to open the binding mechanism it is necessary to push the cover bar completely down from the cover plate, as it might otherwise also be bent. This has the result that after every removal of a sheet, the cover bar then has to be threaded back intricately on to the cover plate.
From the disadvantages of the described prior art arises the problem underlying the invention of so improving a binding device of this type that the cover profile rail can if possible remain connected to the cover plate even for the removal of one or more sheets, so that handling of the binding device is further simplified. Furthermore, the binding device is to be so formed that the risk of accidental damage due to incorrect handling is as small as possible.
This problem is solved according to the invention in that the cover profile rail is divided into two in its longitudinal direction, in such a manner that the two parts are mountable on the cover plate from opposite ends.
Since by dividing the cover profile rail the effective length of a part thereof is significantly reduced, the unfavourable leverage between the cover plate and the cover bar pushed down by the central binding region thereof is reduced, so that there is no risk of damage to the binding mechanism, even if both cover profile rail parts are not pushed down completely by the cover plate. Therefore handling is eased, since after removal or sorting of one or more sheets the cover profile rail does not have to be pushed back on to the cover plate in a time-consuming manner, but rather the cover profile parts remaining therein only have to be pushed back together.
It has been found advantageous that the cover profile rail is divided centrally so that the cover profile rail parts have an identical shape. By this step it can be achieved that both cover profile rail parts are produced with the same injection mould, so that the cost of manufacturing injection moulds is minimal in spite of the increase in number of moving parts of the binding device according to the invention.
It is within the scope of the invention that the cover profile parts have on their impact edge a respective projection which extends roughly over half their length and which corresponds to a recess in the other section of the edge. Thus a visibly tight connection is achieved between the two cover profile rail parts, so that the cover plate is not visible even if the cover profile rail parts are slightly displaced.
Further advantages are achieved if the cover profile rail parts have in the region of their edge profiling which increases the skid-resisting properties, e.g. in the form of fluting. During the opening and closing movement of the cover profile rail parts, their region abutting the edge undergoes permanently guidance along the common cover pate, so that this region is particularly suited to actuation of the cover profile rail parts. Since the cover profile rail parts due to their small cross-section can be touched particularly on the surface, but not actually grasped, the profiling according to the invention ensures adequate friction locking during opening or closing.
It has further proved advantageous that the profiled grip regions are provided on the upper face as well as on both longitudinal edges of the cover profile rail parts. Thus a person has the option for actuation of only placing one finger on the cover profile rail part concerned or to grasp both its longitudinal edges with two fingers.
The user-friendliness can be further increased if the profiled grip regions are formed proud. In this case, the friction-locking effect of the profiling is complemented by positive locking on the shoulder formed by the proud region, so that the reliability in actuation is further improved.
The invention permits an improvement in that the profiled and/or proud grip regions have an arrow-like shape pointing in the insertion direction. Thus these regions indicate unequivocally the closing direction of the cover profile rail parts according to the invention, and these arrows can complement one another in the fully pushed-together state to form an xe2x80x9cXxe2x80x9d, which shows at a glance that the cover profile rail is closed.
The invention further provides that the undercut of the cover profile rail parts is guided continuously round its peripheral end face. Thereby, the closing movement of a cover profile rail part is limited, even if the other cover profile rail part is still open, so that these cannot assume any undefined positions. Furthermore, this encompassing undercut increases the strength of the respective cover profile rail part in the transverse direction, so that unwanted transverse arching is avoided.
The invention offers the further option of giving the cover profile rail parts a perforation each, which lies flush with a respective perforation on the base plate and the cover plate. These perforations on the one hand have the purpose of permitting an additional option of depositing the bound stack in a file or the like, on the other hand the cover profile rail parts form in this case positive locking with the clips of the file concerned and are thereby fixed also in their sliding direction along the cover plate, so that accidental mounting is fully excluded.
The invention can be developed further in that the cover profile rail parts have at the regions adjacent to the edge projections which extend into the undercut region and which can pass into engagement with lateral lugs and/or shoulders on the longitudinal edges of the cover plate in order thereby to counteract opening movement of the cover profile rail part concerned. This design feature serves the purpose of preventing unintentional detachment of the cover profile rail parts from the cover plate, even if the sliding movement is not suppressed by clips of a hole punch penetrating corresponding perforations. In such a case, even if a file is being transported or the like, no parts of the binding mechanism according to the invention can be lost, so that their operativeness is permanently ensured.
This design specification can be realised if at the longitudinal edges of the cover plate close to their end faces shoulders are provided which widen towards the same and which in the open position of the cover profile rail parts pass into contact with the projections projecting into the undercut region and thereby define the opening movement. Since the shaping elements of the cover plate counteracting detachment of the cover profile rail parts from the cover plate are formed as a shoulder, they acquire a maximum of strength, so that unwanted deformation of the cover plate in this region is almost impossible and the cover profile rail parts cannot slide beyond the respective shoulders unnoticed. Since, on the other hand, these shoulders are disposed preferably laterally respectively outside inner perforations for the binding of individual sheets of the respective document stack, the two cover profile rail parts can however be pulled so far apart that the binding tongue plates can be comfortably raised and then the cover plate can be then raised with the cover profile rail parts suspended thereon in order to remove individual sheets of the document stack or to add further sheets.
In a further improved embodiment, at the longitudinal edges of the cover plate, close to its centre, lateral lugs can be provided, behind which the projections of the cover profile rail parts projecting into the undercut region can engage for locking in their closed position.
These lugs permit one or both cover profile rail parts to be fixed in the closed position, so that the opening forces acting during a storage period on the cover profile rail parts are absorbed, even if the storage is not effected in a file whose clips penetrate peripheral perforations of the various layers of the binding mechanism according to the invention.
Particularly in this last embodiment, additional leading eyes can be provided on the longitudinal edges or on the upper face of the cover profile rail parts close to their butt joint, through which a wire, e.g. provided with leading, can be threaded, so that opening of the cover profile rails necessarily brings about destruction of the leading and is therefore immediately recognisable.
Preferably, at both longitudinal edges of the cover profile rail parts such leading eyes are provided, so that with the use of identical cover profile rail parts respectively two eyes are available on the same longitudinal edge of the cover profile rails. Although a similar effect could be achieved by providing an eve on the tipper face of the cover profile rail parts, this would lead to an additional increase of the structural height of the binding mechanism according to the invention, so that the depositing capacity of a file would be reduced. This disadvantage can be substantially avoided by disposing the leading eyes on the longitudinal edges of the cover profile rail parts.
The invention permits a further embodiment in that the cover plate has roughly centrally between the two end faces a widening, such that the projections abutting the same in the closed position and projecting into tile undercut region, of the cover profile rail parts compress the longitudinal edges of the cover plate, forming a slight transverse arching thereof. Since the cover profile rail parts engage under the cover plate, this could be lifted from the document stack so that an unattractive convexity of the centrally divided cover device might arise. By the transverse arching of the cover plate bent up in the region of its longitudinal edges, the cover plate gains its tension, which favours a straight-stretched shape of the cover plate and therefore also of the cover profile rail mounted thereon, so that also in spite of its division, the individual cover profile rail parts adopt a position exactly flush with one another, which promotes the compactness of the document stack bound together.
By the invention, an arrangement is preferred wherein the cover plate has in the region between its inner perforations a groove-like recess for the insertion of the bent-back binding tongue ends. Since this recess is formed continuously preferably between the inner perforations, the binding tongue ends can fit therein, irrespectively of how thick the bound document stack is. The important point for this is in particular that the cross-section of the groove-like recess corresponds roughly to the cross-section of the binding tongue ends or is slightly larger. In such a case, the cover profile rail parts can slide comfortably beyond the bent-back binding tongue ends, and catching thereof is in any case prevented by the fact that the two cover profile rail parts are only pushed respectively as far as the centre of the cover plate and in this case automatically press the binding tongue ends downwards.
Finally, it corresponds to the teaching of the invention that the cover plate and/or the cover profile rail parts are extended beyond the outer perforations, in particular preferably about by 1.5 to 2.5 times the width of the cover plate or about by 3 to 4 times the perforation diameter. This ensures that the opened cover profile rail parts always remain mounted on the cover plate by a sufficient amount, even if they are pulled out up to the shoulder defining, the opening movement, so that the forces exerted on the cover plate acting as a guide by the inner faces of the undercuts of the cover profile rail parts remain small and therefore damage to the binding mechanism is substantially eliminated even during incorrect handling.